title: Measurement of exhaled nitric oxide in a general population sample: a comparison of the Medisoft HypAir FE(NO) and Aerocrine NIOX analyzers.
abstract: OBJECTIVE
  Measuring the fraction of nitric oxide in exhaled breath (FE(NO)) is increasingly utilized to assess airway inflammation in asthma. The primary aim of this study was to compare exhaled nitric oxide measurements obtained using two devices from different manufacturers, that is, the recently marketed portable and electrochemical-based Medisoft HypAir FE(NO) and the well-established chemiluminescence-based Aerocrine NIOX analyzer, in an unselected population.
  
  
  METHODS
  FE(NO) measurements were conducted in 106 subjects (86 healthy; 20 asthmatic; 56.6% atopic). Atopy and health status were assessed by skin prick tests and questionnaire, respectively.
  
  
  RESULTS
  The two instruments showed strong correlation over a wide range of FE(NO) measurements (8-261.3 ppb with the HypAir, 5.6-156.8 ppb with the NIOX; r = 0.98; p < .0001). This correlation was observed in the population as a whole, as well as in healthy non-atopics, healthy atopics, and atopic asthmatics when considered separately. The measurements on the HypAir FE(NO) were consistently 1.6 times (95% CI 1.11-2.05) higher than those obtained with the NIOX.
  
  
  CONCLUSIONS
  FE(NO) measurements obtained with the HypAir FE(NO) correlated well with the NIOX, but were approximately 1.6 times higher. Therefore, a conversion factor is required if results are to be compared with the NIOX instrument.
authors.affiliation: Centre for Public Health Research, Massey University, Wellington, New Zealand. C.R.Brooks@massey.ac.nz
authors.forename: Collin R
authors.initials: CR
authors.lastname: Brooks
authors.forename: Shirley-Belle M
authors.initials: SB
authors.lastname: Brogan
authors.forename: Christine J
authors.initials: CJ
authors.lastname: van Dalen
authors.forename: Phillipa K
authors.initials: PK
authors.lastname: Lampshire
authors.forename: Julian
authors.initials: J
authors.lastname: Crane
authors.forename: Jeroen
authors.initials: J
authors.lastname: Douwes
mesh_terms: D000328:Adult; D001249:Asthma / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D001944:Breath Tests / Q000295:instrumentation*; D004563:Electrochemistry / Q000295:instrumentation*; D045853:Exhalation; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D008163:Luminescent Measurements / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide
chemical_list: D009569:Nitric Oxide